this is another design from Bart Hopkin's book "Making
Simple Musical Instruments". at some point i misspelled his
"rumba", and the change has stuck. it is a marimbula: a giant bass
thumb piano or kalimba, of a sort popular in the Caribbean.
the box is made from a lovely streaked piece of poplar found at
a local home-supply store; unforunately, the pictures don't pick up
the hints of green and purple. the soundboard and back are oak
plywood, from the same piece used to build the zouk. the keys are 1/8th and 3/32 inch music
wire (actually steel rods). the decorative sound hole was the
result of purchasing a proper drill press; fortunately, the tone
seems not to have suffered as a result.
Bart's design features a heavy bridge and light soundboard,
resulting in a staccato tone and surprising amount of low frequency
sound pressure; listeners are often amazed that there is no
electric amplification involved. his mounting design, using bolts
and a U-shaped loop on the keys makes it easy to adjust tuning.
there are two full chromatic octaves. note that some of the keys
are missing in the phototgraph: they are in the shop waiting to be
polished, after a vigorous session of plucking with some
jury-rigged metal picks.
samples, loops, and Reason/Mach5 banks coming soon...